Finding the way: Sensory adaptation during bacterial mechanotransduction

寻找方法：细菌机械传导过程中的感觉适应

• 批准号: 10744926
• 负责人: Joanne N. Engel
• 金额: $ 74.24万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-15 至 2028-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10744926
• 关键词: Acute; Acute Pneumonia; Anti-Bacterial Agents; Antibiotic Resistance; Bacteria; Binding; Binding Proteins; Biology; Chemoreceptors; Chemotaxis; Complex; Cues; Cyclic AMP; Environment; Enzymes; Escherichia coli; Event; Exhibits; Exposure to; Grant; Health; Homeostasis; Homologous Gene; Hour; Human; Infection; Knowledge; Ligand Binding; Ligands; Link; Locomotion; Mediating; Methylation; Methyltransferase; Modeling; Molecular; Motion; Multi-Drug Resistance; Nosocomial Infections; Nutrient; Output; P-methyltransferase; Periodicity; Phosphorylation; Pilum; Process; Production; Pseudomonas; Pseudomonas aeruginosa; Pseudomonas aeruginosa infection; Publishing; Regulation; Role; Rotation; Sensory; Short-Term Memory; Signal Transduction; Site; Stimulus; Surface; Swimming; System; Testing; Therapeutic; Traction; Virulence; cell motility; demethylation; in vitro activity; mechanical signal; mechanotransduction; memory process; mouse model; mutant; novel; novel therapeutic intervention; opportunistic pathogen; programs; protein-histidine kinase; recruit; response; small molecule

Abstract Sensory adaptation is a short-term memory process by which a signaling system returns to its pre-stimulus level despite ongoing exposure to the input signal. Although well-characterized in bacterial chemotaxis, little is known about how adaptation operates in the other bacterial signaling systems. A better understanding of how adaptation operates in these systems will provide new fundamental knowledge and could identify new therapeutic approaches. We focus on mechanosensing, which is critical for surface colonization and infection in Pseudomonas aeruginosa (PA), a leading cause of multi-drug resistant nosocomial infections and a significant health threat. PA uses the Pil-Chp mechanosensing system to transduce a mechanical signal that drives twitching motility and cAMP production to modulate a virulence program upon surface contact. How adaptation functions in this system, or mechanosensing in general, is unexplored. We propose to dissect the mechanism and role of adaptation in the Pil-Chp system because (i) The core enzymatic machinery of the mechanosensory adaptation system, the methylating enzyme PilK and demethylating enzyme ChpB, are conserved but its regulation appears to be distinct from the E. coli chemotaxis system; (ii) This system affords the opportunity to understand how adaptation is deployed in response to surface contact; and (iii) The Pil-Chp system contributes to virulence in a murine model of acute pneumonia, demonstrating its relevance to human PA infections. We discovered that PilK acts as a methylase and ChpB acts as a demethylase for the PilJ chemoreceptor to control the two outputs. Unlike in chemotaxis, the methylase and demethylase exhibit inverse spatial localization. Our studies support a model in which the PilK methylase localizes to the lagging pole, where the PilJ chemoreceptor would be methylated and poised to be activated. In contrast, the ChpB demethylase is recruited to the leading pole by interactions with the response regulator PilG. PilG is required for coordinating TFP extension and retraction at the leading pole. This localization would lead to temporally and spatially restricted PilJ demethylation at the leading pole. PilJ activity would be dampened, potentially facilitating PilG relocalization to the lagging pole and reversals. Thus, sensory adaptation in the Pil-Chp system is fundamentally different from adaptation in E. coli chemotaxis in that it uses temporal AND spatial cues. We will test this hypothesis as follows: Aim 1. Link PilJ methylation states to PilJ activity and outputs. Aim 2. Determine how the response regulator PilG regulates the ChpB demethylase. Aim 3. Test whether the PilK methylase is regulated by MapZ, a c-di-GMP binding protein, to link twitching and flagellar motility.

抽象的 感觉适应是一个短期记忆过程 尽管持续暴露于输入信号，但刺激性水平。虽然符合特征 细菌趋化性，关于适应如何在其他细菌信号传导中运作的知之甚少 系统。更好地了解适应在这些系统中的运作方式将提供新的 基本知识，可以识别新的治疗方法。我们专注于 机械感应，这对于假单胞菌的表面定植和感染至关重要 铜绿（PA），多药耐药性医院感染的主要原因和显着的 健康威胁。 PA使用PIL-CHP机械传感系统来传递一个机械信号，该信号 驱动抽搐的运动性和营地生产以调节表面上的毒力计划 接触。适应性如何在该系统中的功能或一般的机械感应均未开发。 我们建议剖析适应在PIL-CHP系统中的机制和作用，因为（i） 机械感觉适应系统的核心酶促机制，甲基化 酶Pilk和脱甲基化酶CHPB是保守的，但其调节似乎是 与大肠杆菌趋化系统不同； （ii）该系统提供了理解的机会 如何通过表面接触来部署适应性； （iii）PIL-CHP系统 在急性肺炎的鼠模型中有助于毒力，证明了其与 人类PA感染。我们发现PILK充当甲基酶，CHPB充当 PILJ化学感受器的脱甲基酶控制两个输出。与趋化性不同， 甲基化酶和脱甲基酶表现出反向空间定位。我们的研究支持模型 Pilk甲基酶定位于滞后杆，PILJ化学感受器将是 甲基化并准备好被激活。相反，将CHPB脱甲基酶招募到 通过与响应调节剂PILG相互作用来领导极。 PILG是协调所必需的 TFP伸展和撤回领先的杆。这个本地化将导致时间上，并且 领先的杆子在空间限制的PILJ脱甲基化。 PILJ活动将被抑制， 有可能促进PILG重新定位到滞后的杆和逆转。因此，感觉 PIL-CHP系统的适应与大肠杆菌趋化性的适应根本不同 因为它使用时间提示和空间提示。我们将测试此假设如下：AIM 1。 PILJ甲基化向PILJ活性和输出呈现。目标2。确定响应方式 调节器PILG调节CHPB脱甲基酶。 AIM 3。测试PILK甲基酶是否为 由MAPZ（一种C-DI-GMP结合蛋白）调节，以将抽搐和鞭毛运动连接起来。